The present invention is directed to heat sinks in general, and more particularly heat sinks for use in dissipating waste heat generated by electrical or electronic components and assemblies.
High power electrical and electronic components continue to have an increasing demand for higher power dissipation within a relatively confined space. In order to provide for such higher power dissipation requirements while remaining suitably compact, several levels of thermal management are usually required at the device, sub-assembly and component level.
At the component level, various types of heat exchangers and heat sinks have been used that apply natural or forced convection or other cooling methods. One type of heat sink for electrical or electronic components employs a spreader plate that has a folded fin attached thereto that can be formed from a continuous strip of metal in an accordion style. The folded fin is placed on the top surface of the spreader plate such that the folds of the folded strip are abutted to the top surface of the spreader plate and then typically affixed to the spreader plate by metallurgical bonding. An electric fan is then placed in proximity to the side of the heat sink and air is either drawn or blown through the passages formed by the fins and convolutions.
There are certain inefficiencies associated with this type of design, the primary inefficiency being that the air flow does not necessarily contact all flat surfaces of the folded fin. Thus a folded fin heat sink is desired that is easy to fabricate and assemble while also providing for improved airflow and thermal conductivity away from the electronic device being cooled.
One aspect of the present invention is a heat sink for cooling electrical or electronic devices. The heat sink comprises a spreader plate having a top surface and having a bottom surface for attaching to the electronic device. A folded fin formed from a strip of heat conducting material comprising alternating planar portions and curved portions has one edge abutted to the top surface such that the curved portions extend upwardly from the top surface substantially at a right angle.
Another aspect of the present invention is a method of fabricating a heat sink for electrical or electronic devices. The method comprising the steps of providing a spreader plate having a top surface and a bottom surface and further having opposing sides and producing a plurality of slots in the top surface of the spreader plate wherein the slots extend between the opposing sides of the spreader plate. A folded fin is formed wherein the folded fin has a plurality of alternating curved portions and planar portions. The edges of the planar portions are inserted into the slots such that one planar portion of the folded fin is inserted in each slot in the spreader plate and that the curved portions extend beyond the opposing sides and then affixing the planar portions to the spreader plate.
Yet another aspect of the present invention is a method of fabricating a heat sink for electrical or electronic devices comprising the steps of providing a spreader plate having a top surface and a bottom surface and further having opposing sides and forming a folded fin wherein the fin has a plurality of alternating curved portions and planar portions. One side of the folded fin is placed on spreader plate such that the planar and curved portions are substantially perpendicular to the top surface. The folded fin is then affixed to the spreader plate.
These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings.